“He has always wanted to be a director,” reads the Internet Movie Database profile of Alfonso Cuar‪ón, “and also an astronaut.” Cuar‪ón’s double fantasy comes true—and another dream, the moviegoer’s—in Gravity, a space epic of desperate peril and profound wonder.

Gravity opens the Venice Film Festival this evening with the same blast of astonishment that greeted Ang Lee’s Life of Pi when it launched last year’s New York Film Festival. Both are thrilling 3-D dramas of survival in a hostile environment, testaments to human grit and groundbreaking technical ingenuity. Both are the rare movies that need to be seen once for the “Wow!” factor and a second time to try figuring out how Cuar‪ón and his technical savants managed to make the impossible seem so cinematically plausible. No one dared to imagine this before; yet here it is, vividly realized. You are there, inside the awe and dread.

Pi, you’ll recall, was alone on a small boat in the stormy Pacific, his only companion a ravenous Bengal tiger. Sandra Bullock, as NASA scientist Ryan Stone, is stranded in space—no air, no sound, no connection to Mission Control—with George Clooney. So it could be worse.

Having served on shuttle flights since 1996, Clooney’s Matt Kowalsky is the bantering veteran, Ryan the novice: old cop, young cop. Earlier, he had transmitted a creepy, Apollo 13 joke: “Houston, I have a bad feeling about this mission.” But he also wants to reassure Ryan. “You’re the genius up here,” this Buzz Lightyear tells the Doctor Newbie. “I only drive the bus.” And he hopes she can enjoy the spectacle of being 372 miles above her shimmering home. As he rightly says, “Can’t beat the view.”

As Ryan works at fixing a glitch on the space station’s jutting metal arms, a message comes through from their ground control (Ed Harris, himself a movie astronaut 30 years ago in The Right Stuff): “Mission abort.” Debris from a satellite shot down by the Russians is headed their way; and, as bright chunks fly past, Matt still jokes: “Half of North America just lost their Facebook.” The laughter turns to terror when the rest of Matt and Ryan’s crew is killed. The space station arm jerks lose, and Ryan spins wildly around, finally catching Matt’s arm. Now they are tethered on a literally death-defying Cirque du Soleil bungee cord. They have lost contact with Mission Control, as well as access to their oxygen supply. Alone together, with time and options running out.

This amazing 13-min. sequence at the very beginning of Gravity is shown in a single shot. To say this is a marvel of camerabatics, of visual choreography, animation and physical acting (Bullock and Clooney worked on wires in front of a green screen) is to undersell Cuar‪ón’s gift as a storyteller who takes the audience on a nail-gnawing space flight. He’s a cinematic astronaut whose Mission Control is his retinue of visual enablers, led by Special Effects wizard Tim Webber. As the director told Entertainment Weekly’s Jess Cagle, “Each single bit of film is a different technology.”

Beyond technology, Cuar‪ón plays daringly and dexterously with point-of-view: at one moment you’re inside Ryan’s helmet as she surveys the bleak silence, then in a subtle shift you’re outside to gauge her reaction. The 3-D effects, added in post-production, provide their own extraterrestrial startle: a hailstorm of debris hurtles at you, as do a space traveler’s thoughts at the realization of being truly alone in the universe.

[WARNING FOR (VERY VEILED) SPOILER:] Like Life of Pi, and J.C. Chandor’s All Is Lost—which manages the even bolder narrative trick of stranding a sailor (Robert Redford) with neither words nor backstory—Gravity eventually becomes a story of self-reliance, of finding ways to survive and a reason to live. When Ryan reaches a Russian space station and sheds her astronaut gear until she’s down to Ripley’s undies in Alien, she slowly revolves, eyes closed, in a fetal position: a child waiting to be born, or die. At the end of the movie, an ancient astronaut emerges from the sea, as if to recapitulate the evolution of humankind from sea creature. [END OF TORTUOUSLY VEILED SPOILER ALERT.]

Some movies take forever to make. Gravity, which Cuar‪ón wrote with his son Jon‪ás, was in pre-production soon after the director finished Children of Men in 2006, went through two studios and more than a dozen actors for the main roles. Robert Downey, Jr., was to play Matt but dropped out in 2011, allowing Clooney to bring his nonpareil charm, bravado and maturity to the role. Cuar‪ón offered the Ryan part to Angelina Jolie, twice, and then to Natalie Portman, Jennifer Lopez, Rachel Weisz, Marion Cotillard, Carey Mulligan, Blake Lively, Scarlett Johansson, Olivia Wilde—everybody. When these actresses see what Bullock has been given in the role, and the fiery commitment she gives to it, they should all whisper a sincere, Rick Perry-style “Oops.”

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Today’s other entry, Venezia 70: Future Reloaded, comprises short films, a minute or so each, from 70 different directors, including Bernardo Bertolucci, Ermanno Olmi, Catherine Breillat, William Friedkin, Atom Egoyan, Paul Schrader, Todd Solondz and the omnipresent James Franco. Many of these auteurs mourn the death of classic 35mm film in the flowering or festering of the digital age. Yes, there are few “films” at the Venice Film Festival. Even the retrospective selections, such as Roberto Rossellini’s Paisan and Friedkin’s Sorcerer, have been restored digitally.

We should mourn the demise of a glorious century or more, when “film” meant the passage of celluloid or acetate, at 24 frames per second, through the sprockets of a projector. Now it’s almost all on disc, not pictures but pixels. But what Avatar achieved—and Rise of the Planet of the Apes and Life of Pi and now Gravity, each outdoing its predecessor in the filmmaker’s eternal quest to astonish us—represents a triumph of digital technology and human artistry. Cuar‪ón shows things that cannot be but, miraculously, are, in the fearful, beautiful reality of the space world above our world. If the film past is dead, Gravity shows us the glory of cinema’s future. It thrills on so many levels. And because Cuar‪ón is a movie visionary of the highest order, you truly can’t beat the view.

I think the role was only formally offered to Angelina Jolie and Natalie Portman before Sandra Bullock. I remember reading about the casting on Deadline.com and Variety, and after Jolie and Portman passed, Marion Cotillard, Blake Lively, Scarlet Johannson, and Olivia Wilde all auditioned for it but weren't offered the part. I don't know about Rachel Weisz or Jennifer Lopez.